苍白球靶点立体定向术磁共振定位

Stereotactic MRI Imaging of the Pallidal Target

目的 探讨用新的一种立体定向MRI成像技术个体化直接显示定位苍白球靶点。方法 48例帕金森病苍白球毁损术 ,采用快速反转恢复序列MRI连续薄层扫描。直接显示双侧苍白球、壳核和视束 ,测出苍白球边界、内髓板和壳核内缘旁开脑中线距离 ,苍白球腹后核 (PVP)宽度。结果 81%病例苍白球内则部 (Gpi)和外侧部 (Gpe)边界以及内髓板被清晰显示 ,直视下手术靶点定位于PVP中央。不同个体或同个体左右半球苍白球的位置存在显著差异 (P <0 .0 5 ) ,苍白球旁开中线距离变异可达 10mm。PVP宽度左侧大于右侧 (P <0 .0 5 )。结论 单独依前后联合中点 (MCP)解剖间接定位苍白球靶点容易出现偏差 ,而采用MRI特殊序列成像能使苍白球靶区及周围结构直接显示 ,术中PVP微电极侦测穿刺减少 。

Objective To investigate a new stereotactic imaging technique to individually visualize the pallidal target before surgery. Methods A turbo inversion recovery sequence was used for 2mm thick contiguous axial scanning. Pallidocapsular border, medial putaminal border, and optic tract were visualized bilaterally in all patients. Results Boundaries of globus pallidus internus, globus pallidus externus, and lamina medullaris interna were clearly visualized in 81% of the patients. The anatomic target point was chosen in the middle of the visualized postroventral pallidum, irrespective of the position of thispoint in relation to commissures. The literalities of pallidocapsular border, lamina medullaris interna, and medial boundary of putamen were measured bilaterally in each patient, and the width of the posteroventral pallidum was assessed. The laterality of structures showed a wide range. The position of the pallidocapsular border varied by up to almost 10mm between the most medial and the most lateral one. There were also variations in the position of the pallidal structures between left and right hemispheres in the same patients. The posteroventral pallidum was slightly more wide on the left than the right side.Conclusion A MRI sequence that enables visualizeation in each individual patient of the target area and its surroundings may contribute to less electrode passes during intraoperative physiological exploration and to more exact location of the lesion in the posteroventral pallidum.